Producing stable solutions of diazotized nitranilins.



snares anew entree.

RICHARD FISCHER, OF LEVERKUSEN', NEAR COLOGNE, GERMANY, ASSIGNOR TO FAR- BENFABRIKEN VORM. FRIEDR. BAYER & ('30., OF ELBERFELID, GERMANY, A COR- BORATION 01E GERMANY.

PRODUCING STABLE SOLUTIONS OF DIAZOTIZED NITRANILINS.

No Drawing. 1

T all whom it may concern Be it known that I, RICHARD FISCHER, doctor of philosophy, chemist, citizen of the German Empire, residing at Leverkusen,

near Cologne, Germany, have invented new and useful Improvements inProducing Stable Solutions, of Diazotized Nitranilins, of

which the following is a specification.

A serious drawback in the use of diazotized nitranilins for dyeing and printingis the fact that the diazo solutions and the printing pastes containing them are rendered very quickly useless. It has now been found that this fault can be remedied in a simple manner by the addition of aromatic sulfonic acids such as naphthalene sulfonic acids or anthraquinone sulfonic acids or of their salts to the diazo solutions. This addition can be made before or after the diazotization of the nitranilins. It is remarkable that for this purpose even relatively small quantities of the sulfonic acids are suficient.

If for instance a naphthalene trisulfonic acid is used, a quantity of this acid amounting to A; or Q; of the weight of the nitranilin used is suficient to secure Specification of Letters Patent.

Application filed February 14, 1912.

Patented Mar. 25, 1913.

Scria1No.677,600.

dyeing mediums of diazotized nitranilins, which process consists in adding to the solutions and pastes containing nitranilins, an aromatic sulfonic acid in quantities which are not sufficient for the formation of neutral salts with the diazo compounds, substantially as described.

2. The process for the production of stable dyeing mediums of diazotized nitranilins, which process consists in adding to the solutions and pastes containing nitranilins, a naphthalene trisulfonic acid in quantities which are not suflicient for the formation of neutral salts with the diazo compounds, substantially as described.

' 3. Process for the production of stable solutions of diazotized nitranilins which comprises adding an aromatic sulfonic acid to the solution before diazotizing.

4. Process for the production of stable solutions ofdiazotized nitranilins which comprises adding a naphthalene trisulfonic acid to the solution before diazotizing.

5. As new articles of manufacture, dyeing mediums comprising nitrodiazobenzenes and a naphthalene trisulfonic acid.

6. As new articles of manufacture dyeing mediums comprising a diazotized nitranilin and a naphthalene trisulfonic acid amounting to 1: to 7; of the weight of the nitranilin.

7 As a new article of manufacture a solution comprising a diazotized nitranilin and a naphthalene trisulfonic acid amounting to i to 2; of the weight of the'nitranilin.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

RICHARD FISCHER. [L. s.]

Witnesses:

ALBERT NUTER, HELEN NUFER. 

